Which equation would generate an exponential decay curve?

An equation that generates an exponential decay curve is typically of the form ( y = ae^{-bx} ), where ( a ) is the initial value, ( b ) is a positive constant, and ( x ) represents time or another independent variable. In this equation, as ( x ) increases, the value of ( y ) decreases exponentially towards zero. Another common form is ( y = a(1 - r)^x ), where ( 0 < r < 1 ) also describes exponential decay.